Allen Kachina, Carlile Simon, Alais David
Department of Physiology, University of Sydney, Sydney, NSW 2106, Australia.
J Acoust Soc Am. 2008 Mar;123(3):1562-70. doi: 10.1121/1.2831774.
To examine whether auditory streaming contributes to unmasking, intelligibility of target sentences against two competing talkers was measured using the coordinate response measure (CRM) [Bolia et al., J. Acoust. Soc. Am. 107, 1065-1066 (2007)] corpus. In the control condition, the speech reception threshold (50% correct) was measured when the target and two maskers were collocated straight ahead. Separating maskers from the target by +/-30 degrees resulted in spatial release from masking of 12 dB. CRM sentences involve an identifier in the first part and two target words in the second part. In experimental conditions, masking talkers started spatially separated at +/-30 degrees but became collocated with the target before the scoring words. In one experiment, one target and two different maskers were randomly selected from a mixed-sex corpus. Significant unmasking of 4 dB remained despite the absence of persistent location cues. When same-sex talkers were used as maskers and target, unmasking was reduced. These data suggest that initial separation may permit confident identification and streaming of the target and masker speech where significant differences between target and masker voice characteristics exist, but where target and masker characteristics are similar, listeners must rely more heavily on continuing spatial cues.
为了检验听觉流是否有助于解蔽，我们使用坐标反应测量（CRM）[博利亚等人，《美国声学学会杂志》107, 1065 - 1066 (2007)]语料库测量了在有两个竞争说话者的情况下目标句子的可懂度。在控制条件下，当目标和两个掩蔽声在正前方并置时，测量言语接受阈值（正确率50%）。将掩蔽声与目标在空间上分开±30度会导致12分贝的空间解蔽效应。CRM句子在第一部分包含一个标识符，在第二部分包含两个目标词。在实验条件下，掩蔽说话者开始时在空间上以±30度分开，但在评分词之前与目标并置。在一个实验中，从一个混合性别的语料库中随机选择一个目标和两个不同的掩蔽声。尽管没有持续的位置线索，仍存在4分贝的显著解蔽效应。当使用同性别的说话者作为掩蔽声和目标时，解蔽效应降低。这些数据表明，在目标和掩蔽声的语音特征存在显著差异时，初始分离可能允许对目标和掩蔽声语音进行可靠的识别和流处理，但当目标和掩蔽声特征相似时，听众必须更依赖持续的空间线索。
